1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and a program. More particularly, the invention relates to an image processing apparatus, an image processing method, and a program such that when image signals are interpolated based on their motion vector, the image quality of the interpolated image signal is improved.
2. Description of the Related Art
FIG. 1 schematically shows a typical structure of an ordinary image processing apparatus 1.
In FIG. 1, the image processing apparatus 1 is made up of a frame rate converting section 11, a panel driving section 12, and a display panel 13. In operation, the image processing apparatus 1 enhances for display purposes the frame rate of image signals that are pixel-specific digital signals representative of externally input, chronologically ordered frame-by-frame images.
Given an externally input image signal, the frame rate converting section 11 carries out a frame rate enhancement process for raising the frame rate (i.e. cycle) of the received image signal. More specifically, the frame rate converting section 13 first performs a frame interpolation process on the image signal supplied from the outside. The image signal resulting from the interpolation is output to the panel driving section 12 as an image signal that is interposed chronologically between externally input image signals. The process makes the frame rate of the input signal to the panel driving section 12 higher than the frame rate of the signal entering the frame rate converting section 11.
The panel driving section 12 performs D/A (digital/analog) conversion and other processes on the image signal supplied by the frame rate converting section 11. The resulting analog signal is used by the panel driving section 12 to drive the display panel 13 such as a liquid crystal display (LCD) panel whereby frame-by-frame images are displayed.
The frame rate enhancement process performed by the frame rate converting section 11 in FIG. 1 is indispensable for improving the image quality of chronologically ordered image signals. The same holds true for frame interpolation used in the process for compensating the motions of such chronologically ordered image signals.
One way to implement the frame interpolation process involves first detecting a motion vector from chronologically input image signals and then using the detected motion vector to interpolate image signals at certain points in time between chronologically ordered image signals (as disclosed in Japanese Patent Laid-open No. 2001-42831).
The motion vector is detected illustratively using the so-called block matching method whereby chronologically ordered image signals are compared with one another. In cases such as when a rigid body is moving, the motion vector of the body is accurately detected.